Adjustable support for drawing-boards.



A. HOFFMAN.

ADJUSTABLE SUPPORT FOR DRAWING BOARDS.

APPLICATION FILED SEPT. 1, 1910.

979,070. Patented Ded.20, 1910.

2 BHBETS-BHEETL A. HOFFMAN.

ADJUSTABLE snrron'r FOR DRAWING BOARDS.

APPLIOATION I'ILBD SEPT. 1. 1910.

979,070, Patented Dem 20, 1910.

2 BHBETBSHEET 2.

ADOLPH HOFFIVIAN, OF COLUMBUS, OHIO.

ADJUSTABLE SUPPORT FOR DRAWING-BOARDS.

Application filed September 1, 1910.

Specification of Letters Patent.

Patented Dec. 20, 1910.

Serial No. 580,015.

To all whom it may concern:

Be it known that I, AnoLrH HOFFMAN, a citizen of the United States, residing at Columbus, in the county of Franklin and State of Ohio, have invented certain new and useful Improvements in Adjustable Supports for Drawing-Boards; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which itappertains to make and use the same.

This invention relates to improvements in adjustable supports for drawing boards and the like.

One ob ect of the invention is to improve the construction of the supports shown in U. S. Letters Patent #956,095 and #956,096 granted to me April 26, 1910 whereby more eflicient and reliable clamping devices are provided for holding the board at the desired ele *ation and angle and for attaching the device to a table, chair or other support.

With the foregoing and other objects in view, the invention consists of certain novel features of construction, combination and arrangement of parts as will be more fully described and particularly pointed out in the appended claim.

In the accompanying drawings: Figure 1 is a side view of my improved support showing the same arranged for securing the board to the edge of a table or similar support; Fig. 2 is a front view; Fig. 3 is a central vertical longitudinal sectional view of the same on an enlarged scale; Fig. 4: is a horizontal sectional view taken immediately above the clamp for attaching the device to a table or other support; Fig. 5 is a side view showing the manner in which the device is attached to a chair; Fig. 6 is a front view of the same and a portion of the standard; Fig. 7 is a detail view of the socket member of the support; Fig. 8 is a similar view of the attaching clamp for the support. Fig. 9 is a perspective view of the lower side of the board and the supporting spider arranged thereon. Fig. 10 is a detail vertical section on the line 10-10 of Fig. 7.

In the illustrated embodiment of the invention, I provide a socket member 1 having on its lower end and projecting from its opposite sides a pair of apertured bracket lugs 2. which are spaced a suitable distance apart and have formed therein alined transversely disposed pin holes 3. Arranged between and having its opposite ends engaged with the apertures in the bearing lugs is a short pivot shaft 4, the ends of which are secured in the lugs 2 by fastening pins 5 inserted through the pin holes 3 in the lugs and through the ends of the shaft, as shown.

In one side of the socket member 1 midway between its upper and lower ends and projecting laterally therefrom is a stud bolt (3. In the adjacent side of the socket mem ber above and below the bolt 6 are formed semi-circular passages 7 which communicate with the bore or passage of the socket.

Slidably mounted on the bolt 6 is a clamping member 8 comprising a short tube or sleeve 9 which engages and slides on the bolt. On the opposite sides of the sleeve 9 are formed offset clamping lugs 10 the ends of which project beyond the inner end of the sleeve and are adapted to engage the passages 7 formed in the socket. The lugs 10 have a cross sectional shape corresponding to the shape of the passages 7. The outer portion of the stud bolt 6 is threaded and on said threaded end is adapted to be screwed a winged clamping nut 11 which when screwed up on the end of the bolt is adapted to engage and force the clamping member 8 inwardly and the lugs 10 thereon into the vertical bore or passage of the socket 1.

Pivotally mounted in the socket 1 is a board supporting post 12 having formed on its upper end an annular stop flange 13 and a series of radially projecting spider arms 14 the outer portions of which are secured in any suitable manner to the under side of the board 15. By mounting the board in the socket in the manner described the board may be revolved in either direction and when at the desired position is fastened by tightening up the nut 11 which will force the lugs 10 of the clamping member 8 into engagement with the post 12 thereby firmly fastening the spider and board.

The pivot shaft 4: when inserted through the apertured bracket lugs 2 is engaged with the horizontal passage of a T coupling 16 in the vertical passage of which is secured the upper end of a supporting standard 17. By thus pivotally connecting the socketmember 1 with the standard 17 said socket member and the board carried thereby may be tilted to the desired angle. In order to secure the socket member and board in the position to which they have been tilted, I

provide a set screw 18 which is arranged in a threaded aperture formed in one side of the horizontal member of the T coupling and is adapted to be screwed into engagement with the pivot shaft I thereby holding the same and the socketmember against turning in the coupling.

It will be readily seen that the construction described and shown produces a very compact arrangement of the parts and reduces the projecting elements to a minimum so that the liability of damage through chance blows is obviated. At the same time, a very extensive adjustment of the parts is permitted and the cost of production is reduced. The clamping member 8 obtains a wide bearing upon the post 12 so that said postwill be securely held in the socket member without any liability of bending the bolt (3 or stripping the threads from the same.

The standard 17 may be of any desired length and is adapted to be slidably engaged with a double screw supporting clamp 19 whereby the board may be attached to a table, chair or other object. The clamp 1.9 comprises a standard receiving tube or sleeve 20 on which are arranged upper clamping lugs 21 and lower l'iearing lugs 22 in which are formed threaded passages adapted to receive clamping screws 2?) of the usual or any suitable construction. In the sleeve 20 ot' the clamp is arranged a set screw 23 adapted to be screwed into engagement with the standard 17 whereby the same is fastened in its adjusted position to support the board at the desired elevation.

In applying the clamp to a table or other object having a projecting ledge, the upper clamping lugs are engaged with the upper side of the ledge while the clamping screws are screwed into tight engagement with the lower side of the ledge thus firmly supporting the board.

In order to secure the drawing board to a chair I preferably provide a supporting board 24 which is slidably mounted in suitable guides 25 secured to the under side of the chair bottom. 'When it is desired to attach the board to the chair the board 24 is drawn out to the desired position and the clamp 19 secured thereto in the same manner as when secured to the ledge of a table.

From the foregoing description taken in connection with the accompanying drawings, the construction and operation of the invention will be readily understood without re quiring a more extended explanation.

Various changes in the form, proportion and the minor details of construction may be resorted to without departing from the principle or sacrificing any of the advantages of the invention as defined in the appended claim.

Having thus described my invention, what I claim is:

The combination of a socket member having diametrically opposite depending apertured ears at its lower end and provided in its upper portion with transverse openings communicating with its bore and having a screw formed thereon and projecting radially outward between said openings, a post fitted in the socket member and provided at its upper end with a spider adapted to be secured to a board and having an annular flange below the spider to rest on the upper end of the socket member, a clamping member fitted on the bolt projecting from the socket member and having lugs entering the openings in said member, a nut mounted on the bolt and bearing upon said clamping member, a pivot bolt secured in and extending between the cars at the lower end of the socket member, a coupling member mounted loosely on said pivot bolt between said ears and having a depending hollow arm, and a standard fitted in said arm.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

ADOLPH HOFFMAN.

Vitnesses H. J. OSSING, V. M. BORROR. 

